Toggle between apps: Use Alt-Tab to switch open programs without touching your mouse. The oldest--and still the best--Windows timesaver.

Navigate app windows: Press Ctrl-Tab to cycle through an application's windows (or through a Web browser's tabs). First cousin of the tip above, and probably the most underrated tip ever.

When in doubt, type it out: If you don't want to hunt through nested menus and the like, you can access most functions, applets, or files the old-fashioned way--by entering them into the Search box. Type Calculator, Control Panel, or even the name of a piece of music on your hard drive, and press Enter.

Full-frontal folders: In Windows Explorer, click Folder Options (located under the Organize menu) to reveal hidden files, show the full path in the title bar, display file extensions, and more.